Question

3- A tiger jumps to catch a crane, if the tiger jumps at 30 degree angle respect to the ground at 25 m/s, what is the tiger’s highest point off the ground?

4- A motorbike is cruising at 20 m/s when suddenly the driver turns the engine up to full throttle. After traveling 5 km, the bike is moving with a speed of 60 m/s. What is the bike’s acceleration in m/s2 , assuming it is a constant acceleration?

5- An 6 hour trip is made at an average speed of 84 km/hr. If the driver drove at at 40 km/hr for the first 2.9 hours, what was the average speed (in km/hr) for the rest of the journey?

6- If you crash your car and it took you 2.5s to go from 60mph to stop, what is your acceleration in this case?

7- A ball is thrown upward, from a roof 90 m above the ground. The ball rises, then falls and strikes the ground some time later. The initial upward velocity of the ball is 53 m/s. Neglecting air resistance, after how many seconds will the ball strike the ground?

8- Joe drives due west at 35 km/hr for 70 minutes, then due north at 60 km/hr for 45 minutes then east at 55 km/hr for 4 ho

Answer 1

3)Given,

theta = 30 deg ; v = 25 m/s

The tiger will follow the path of a projectile and at highest point its velocity will be zero.

The tigers highest point will be given by:

v^2 = u^2 + 2 a H => H = v^2/2a = vy^2/2g

vy = 25 sin30 = 12.5 m/s

H = 12.5^2/2 x 9.81 = 7.97 m

Hence, H = 7.97 m (=8 m aprox)

2)Given,

u = 20 m/s ; v = 60 m/s ; s = 5 km = 5000 m

We know from eqn of motion

v^2 = u^2 + 2 a S

a = (v^2 - u^2)/2 s

a = (60^2 - 20^2)/2 x 5000 = 0.32 m/s^2

Hence, a = 0.32 m/s^2