The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N
D=vt use this equation to get the depth of the skull
The speed of the runner is 300 m /38 seconds. You can simplify this answer to be about 7.9 m/s
Answer:
I don't really know
Explanation:
I really wanted to help you, but then I realized i didnt know how to
Newton's 2nd law of motion:
Force = (mass) x (acceleration)
= (1,127 kg) x (6 m/s² forward)
= (1,127 x 6) newtons forward
= 6,762 newtons forward
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Momentum = (mass) x (speed)
= (69 kg) x (6 m/s)
= 414 kg-m/s
