Answer:
weight
Explanation:
The weight of an object is the force of gravity on the object and may be defined as the mass times the acceleration of gravity, w = mg. Since the weight is a force, its SI unit is the newton. Density is mass/volume.
<u>Acceleration = (change in speed) / (time for the change)</u>
(Note: That's all the Physics there is to this problem.
The rest is all arithmetic.)
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change in speed = (40 - 20) miles/hour = -20 miles/hour
time for the change = 10 minutes
Acceleration = (-20 miles/hour) / (10 minutes) =
<em>-2 miles/hour per minute</em> .
That's a perfectly good and technically correct expression for acceleration.
But obviously the units might make some people dizzy. So let's try to
clean it up a little.
Notice that 10 minutes is 1/6 of an hour.
So we could write the acceleration as
Acceleration = (-20 miles/hour) / (1/6 hour) = -120 miles/hour per hour =
<em>-120 miles/hour² .</em>
You could convert this into any units you like. It's really not a physics problem
any more, it's just an exercise in converting units.
Answer:
361.8 J
Explanation:
= Pulling force applied on the sled by the child = 55 N
= Angle between the direction of pulling force and displacement = 20 deg
= Displacement of the system = 7.0 m
= Work done by the child's pulling force
We know that work done is given as
Answer:
54,000 J
Explanation:
Given,
Power ( P ) = 75 W
Time ( t ) = 12 minutes
To find : Electrical energy ( E ) = ?
t = 12 minutes
= 12 x 60
t = 720 seconds
Formula : -
E = Pt
E = 75 x 720
E = 54,000 J
Therefore,
54,000 J is the electrical energy is used by a 75 W laptop that is operating for 12 minutes.