Answer: 71.43 kilograms
This value is approximate rounded to two decimal places.
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Explanation:
The ground is pushing up with a normal force of 700 N. Because the box is sitting still, this means the force of gravity is pulling the box down with a force of 700N to keep things balanced.
If the force of gravity was greater than 700N, then the box would fall through the ground. If the force of gravity was smaller than 700N, then the box would be accelerated upward. Since neither event is happening, the force of gravity must be equal to the normal force.
Now turn to Newton's second law which says
F = ma
where F is the force, m is the mass and 'a' is the acceleration. We're given the acceleration of gravity is roughly 9.80 m/s^2. So a = 9.80
The force we'll plug in is F = 700. The value of m is unknown, but we can solve for it as such
F = ma
700 = m*9.80
700 = 9.08m
9.80m = 700
m = 700/9.80
m = 71.4285714285714
m = 71.43
The mass is roughly 71.43 kilograms.
Answer:
Velocity of skater after throwing the snowball is 2.57 m/s
Explanation:
Given :
Mass of skater, M = 62.2 kg
Mass of snowball, m = 0.145 kg
Velocity of snowball relative to ground, v = 39.3 m/s
Consider v₁ be the velocity of skater after throwing the snowball.
According to the problem, initially the velocity of skater and snowball is same. So,
Velocity of skater before throwing snowball, u = 2.66 m/s
Applying conservation of momentum,
Momentum before throwing snowball = Momentum after throwing snowball
(M + m) u = Mv₁ + mv
Substitute the suitable values in the above equation.
v₁ = 2.57 m/s
As we know that work done due a force F is given by formula
here F = applied force due to which work is done
d = displacement of object
now here we will have
W = 588 J
d = 1.4 m
now we can find force by above formula
So applied force by milkman is F = 420 N
Answer: neither accurate nor precise
Explanation:
Showing that it should be near 9.8 m/s and the trials aren't near that accuracy, I would say neither.
