Posted by **Aisumi** on Saturday, October 30, 2010 at 2:17am.

Okay the equation for kinetic energy is = 1/2mv^2 so how would i figure this out??

If a semi-truck decreases its speed from 10 m/s to 5 m/s, its new Kinetic Energy is:

a)4 times its old Kinetic Energy

b)2 times its old Kinetic Energy

c)1/2 its old Kinetic Energy

d)1/4 its old Kinetic Energy

okay since the v is half of what it was would it be c????

- Physics kinetic energy -
**Jordan**, Saturday, October 30, 2010 at 10:05am
because v is the only thing changing the value of m is not relevant. to find out what would happen to the energy we compare the differences in v

ie 10^2 = 100

5^2 = 25

since the new v value is a quarter of the previous value the answer is (d)

alternatively, your reasoning before is correct but you have forgotten that the v value is squared ie 0.5^2 = 0.25

## Answer this Question

## Related Questions

- Physical Science - Can someone please check these answers for me? Write T for ...
- science - A ball sitting on the top of a table has potential energy but no ...
- science - A ball sitting on the top of a table has potential energy but no ...
- Physics - A 5.36 kg object falls freely (ignore air resistance), after being ...
- Physics - A 245 g particle is released from rest at point A inside a smooth ...
- physics kinetic energy - a) if a particle's speed decreases by a factor of four...
- Physics - A rolling barrel with initial velocity 20 m/s encounters a hill 10m ...
- physics-energy conservation - when you apply the brakes of a car its kinetic ...
- Physics - Two objects are mocing about so that their total momentum is zero. ...
- Physics - A 1000kg space craft at 500m/s is on a collision course with a 400kg ...

More Related Questions