Question

i need to solve these and I don't understand any of it...help please!​

Answer 1

1. distance=50cm =0.5m

force=10N

work done=fd=10×0.5

=5J

2. P. E. =mgh

500×10×9.8

=49000J

3.K.E.=200J

mass=1kg

K. E. =1/2mv^2

=1/2×1×200×200= 20000J

4.mass=80kg

height or length=15cm

P. E. =mgh= 80×9.8×15

=11760J

5.mass=2.5kg

P. E. =750J

P. E. =mgh

750=2.5×h=300cm

6.mass=60kg

speed=3m/s

K. E. =1/2mv^2

1/2×60×3= 90J

7.K.E.=200J

MASS=1Kg

K. E. =1/2mv^2

200=1/2×1×v^2 =20m/s

8.kinetic energy is reduced by 1/4th

so the new kinetic energy is 500J