You carry a 7.0 kg bag of groceries above the level floor at a constant velocity of 75 cm/s across a room that is room. How much
1 answer:
Answer:
1.97J
Explanation:
Given parameters:
Mass of the groceries = 7kg
velocity of the bag = 75cm/s
Unknown:
Work done to move the bag = ?
Solution:
Work done is the force applied to move a body through a distance in a specific direction:
Work done = Force x distance
In this case, the work done is the kinetic energy applied in pulling the bag.
Kinetic energy is the energy in motion of a body.
Work done = kinetic energy =
where m is the mass
v is the velocity
Now, convert the velocity from cm/s to m/s
100cm = 1m
75 x
= 0.75m/s
Work done = x 7 x 0.75² = 1.97J
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The final velocity of the truck is found as 146.969 m/s.
Explanation:
As it is stated that the lorry was in standstill position before travelling a distance or covering a distance of 3600 m, the initial velocity is considered as zero. Then, it is stated that the lorry travels with constant acceleration. So we can use the equations of motion to determine the final velocity of the lorry when it reaches 3600 m distance.
Thus, a initial velocity (u) = 0, acceleration a = 3 m/s² and the displacement s is 3600 m. The third equation of motion should be used to determine the final velocity as below.
Then, the final velocity will be
Thus, the final velocity of the truck is found as 146.969 m/s.
Answer:
Explanation:
First we have to find the time required for train to travel 60 meters and impact the car, this is an uniform linear motion:
The reaction time of the driver before starting to accelerate was 0.50 seconds. So, remaining time for driver is 1.5 seconds.
Now, we have to calculate the distance traveled for the driver in this 0.5 seconds before he start to accelerate. Again, is an uniform linear motion:
The driver cover 10 meters in this 0.5 seconds. So, the remaining distance to be cover in 1.5 seconds by the driver are 35 meters. We calculate the minimum acceleration required by the car in order to cross the tracks before the train arrive, Since this is an uniformly accelerated motion, we use the following equation: