The distance covered by car is equal to (assuming it is moving by uniform motion) the product between the car's speed and the time of the car ride, 4 h:
where
is the car's speed
is the duration of the car ride
Similarly, the distance covered by train is equal to the product between the train's speed and the duration of the train ride, 7 h:
The total distance covered is S=255 km, which is the sum of the distances covered by car and train:
which becomes
(1)
we also know that the train speed is 5 km/h greater than the car's speed:
(2)
If we put (2) into (1), we find
and if we solve it, we find
So, the car speed is 20 km/h and the train speed is 25 km/h.
By just smiling. It normally makes you look more happy.And if your happy that's positive body languge
Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force
When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
(a) The net force on the shopping cart is zero.
(b) The the force of friction on the shopping cart is 25 N.
(c) When same force is applied to the shopping cart on a wet surface, it will move faster.
<h3>Net force on the shopping cart</h3>
The net force on the shopping cart is calculated as follows;
F(net) = F - Ff
where;
- F is the applied force
- Ff is the frictional force
ma = F - Ff
where;
- a is acceleration of the cart
- m is mass of the cart
at a constant velocity, a = 0
0 = F - Ff
F(net) = 0
F = Ff = 25 N
Net force is zero, and frictional force is equal to applied force.
<h3>On wet surface</h3>
Coefficient of kinetic friction of solid surface is greater than that of wet surface.
Since frictional force limit motion, when the frictional force is smaller, the object tends to move faster.
Thus, the cart will move faster on a wet surface due to decrease in friction.
Learn more about frictional force here: brainly.com/question/24386803
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Answer:
The work done on the suitcase is, W = 1691 J
Explanation:
Given data,
The force on the suitcase is, F = 89 N
The distance Russell dragged the suitcase, S = 19 m
The work done on the suitcase by Russell is equal to the work done on the suitcase to overcome the friction
The work done on the suitcase by Russell is given by the formula
W = F · S
Substituting the given values,
W = 89 N x 19 m
W = 1691 J
Hence, the work done on the suitcase is, W = 1691 J
