Question

Question 1:

A 2-kg wood block is pulled by a string across a rough horizontal floor. The string exerts a tension force of 30 N on the block at an angle of 20º above the horizontal. The block moves at constant speed. If the block is pulled for a distance of 3.0 m, how much work is done by the tension force?

Question 2:

Part A: A spring-loaded toy gun is used to launch a 12.0-g plastic ball. The spring which has a spring constant of 15.0 N/m is compressed 8.00 cm as the ball is pushed into the barrel. When the trigger is pulled the spring is released and shoots the ball back out horizontally. What is the elastic potential energy stored in the spring when it is compressed 8.00 cm?

Part B: Assuming all of the spring potential energy is converted to the kinetic energy of the ball, with what speed will the ball leave the gun?

Answer 1

Question 1

Workdone,

ANSWER:

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Question 2

Part A

Given spring constant ,k =15N/m

Compressed distance ,x =8cm =0.08m

Elastic Potential Energy ,

ANSWER:

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Part B

Given all of the spring potential energy is converted to the kinetic energy of the ball

so

ANSWER:

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