Question

5) Starting from rest, a car accelerates at a constant rate, reaching 88 km/h in 17...

5) Starting from rest, a car accelerates at a constant rate, reaching 88 km/h in 17 s. (a) Find its acceleration. (b) Find how far does it goes in this time.

6) A delivery drone drops a well-cushioned package from a height of 15.7 m onto a customer’s porch. At what speed does the package hit the porch?

7) A diver drops from a 7.44-m high cliff. (a) At what speed does she enter the water? (b) How long is she in the air?

8) A foul ball leaves the bat going straight upward at 22 m/s. (a) How high does it rise? (b) How long is it in the air? Neglect the distance between the bat and the ground.

Homework Answers

Answer #1

Please rate. Thank you!

5. a) Converting speed from km/h to m/s , speed = 88 * 5/18 = 24.44 m/s

Acceleration = (v - u ) / t , where v is final velocity, u is initial velocity, t is time taken

Therefore a = (24.44 - 0) / 17 = 1.43 m/s^2

b) Distance covered = u*t + 0.5 * a* t^2 = 0 + 0.5*1.43*17*17 = 206.35 m

6 ) Taking downward direction as positive,

and using v^2 = u^2 + 2* a *s

u = 0 (since dropped from rest)

v^2 = 2 * g * 15.7 = 314

v = 17.7 m/s

7 . a ) Again using previou formula ,

v^2 = 2 * 10 * 7.44

v = 12.19 m/s

b ) Using s = u*t + 0.5*a*t^2

7.44 = 0 + 0.5 * 10 * t^2

t = 1.22 sec

8 . Taking upward direction as positive.

a ) and using v^2 = u^2 + 2* a * s

v = 0 (at highest point, velocity is 0) , u = 22 m/s , a = -10 m/s^2 (g is acting downwards)

0 = 484 - 2 * 10 * s

s = 24.2 m

b ) Using v = u + a*t

0 = 22 - 10 * t

t = 2.2 seconds

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
I'm trying to check my work. I'm usually able to go to the tutoring center and...
I'm trying to check my work. I'm usually able to go to the tutoring center and have some one look at it but with classes being online I can't. Please help! 1) The muscles in a grasshopper's legs can propel the insect upward at 3.3 m/s. How high can the grasshopper jump? 2) A jetliner touches down at 200 km/h , reverses its engines to provide braking, and comes to a halt 24 s later. What's the shortest runway on...
A car starts from rest and accelerates at a constant rate traveling a distance of 200...
A car starts from rest and accelerates at a constant rate traveling a distance of 200 m in t s. The car continues to accelerate at the same rate for an additional 135 m. If the speed of the car after it has travelled the (200+135) m is 70 m/s, how long t (in s) did the car accelerate for?
A car starts from rest and accelerates at a constant rate traveling a distance of 147...
A car starts from rest and accelerates at a constant rate traveling a distance of 147 m in sec. The car continues to accelerate at the same rate for an additional 158 m. If the speed of the car after it has travelled the (147+158) m is 93 m/s, how long (in secs) did the car accelerate for?
1. A car traveling 69 km/h is 247 m behind a truck traveling 93 km/h. How...
1. A car traveling 69 km/h is 247 m behind a truck traveling 93 km/h. How long will it take the car to reach the track? Calculate to one decimal 2.Suppose one of Napoleon cannons has a muzzle speed of 32m/s. It was aimed at 54 ◦ angle. What height can the cannon ball reach? Use g = 9.8 m/s2 Calculate to one decimal 3.A girl throws a rock horizontally, with a velocity of 13 m/s, from a bridge. It...
A car starts from rest and accelerates at a constant rate travelling a distance of 160...
A car starts from rest and accelerates at a constant rate travelling a distance of 160 m in 6 s. The car continues to accelerate at the same rate for an additional x m. If the speed of the car after it has travelled the (160+ x) m is 92 m/s, how far x (in m) did the car continue at a constant acceleration?
A car starts from rest and accelerates at a constant rate travelling a distance of 210...
A car starts from rest and accelerates at a constant rate travelling a distance of 210 m in 14.9 s. The car continues to accelerate at the same rate for an additional 199 m. What is the speed (in m/s) of the car after it has travelled the (210+199) m?
A sky diver jumps from a high building. He should not release his parachute until his...
A sky diver jumps from a high building. He should not release his parachute until his speed is 30 m/s. When falling the air resistance depends on the speed and is given by a (drag) = 0.003 v2 How far does he drop before reaching a speed of 30 m/s?
A stone falls from rest from the top of a cliff. A second stone is thrown...
A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3 . 2 s later with an initial speed of 62 . 72 m / s. They hit the ground at the same time. (a) How long does it take the first stone to hit the ground? The acceleration of gravity is 9 . 8 m / s 2 . Answer in units of s. (b) How high is...
A proton accelerates from rest in a uniform electric field of 580 N/C. At some later...
A proton accelerates from rest in a uniform electric field of 580 N/C. At some later time, its speed is found to be 3.6 ✕ 106 m/s. (a) Calculate the magnitude of the acceleration of the proton (in m/s2). m/s2 (b) How long (in s) does it take the proton to reach the given speed? s 3. [–/1 Points] DETAILS
An electric vehicle starts from rest and accelerates at a rate of 2.1 m/s2 in a...
An electric vehicle starts from rest and accelerates at a rate of 2.1 m/s2 in a straight line until it reaches a speed of 19 m/s. The vehicle then slows at a constant rate of 1.3 m/s2 until it stops. (a) How much time elapses from start to stop? (b) How far does the vehicle move from start to stop
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT