Question

Assume that g is 10 N/kg and that air resistance and other

Answer 1

Answer:

1) Given acceleration due to gravity as 10N/kg

N/kg is the same as m/s². From W=mg

making g subject ... you have g = W/m

where m is in kg and W is in N

hence we have N/kg

So g=10ms-²

Gravitational Potential Energy=mgh

At height 4m

PE=6 x 10 x 4

=240J.

At height 6m

PE=6 x 10 x 6

=360J.

2) KE=1/2mv²

=1/2 x 6 x 5² =75J

When the speed is doubled... it becomes 2x

so V = 2x5=10ms-¹

KE=1/2 x 6 x 10² =300J.

3) KE=1/2mv²

KE is given as 100J

mass=0.5kg

Making V the subject

you have v² =2KE/m

v²=2 x 100/0.5

v²=400

taking square root

v=20ms-¹.

Have a great day✌