Answer:
When the bag of apples are on the floor, the force of gravity is equal to the force applied in the upward direction.
But when the girl picks up the bag of apples, she applies a force on the bag of apples in the upward direction greater than that of the gravitational force.
Explanation:
Gravitational force for an object is always constant at a specific point. When an object is in the state of rest, there is an equal force opposite to the direction of Gravitational Force.
Now, to lift an object upwards, an external force must be applied that is greater than the force of gravitation.
So, when the girl picks up the bag of apples,
Gravitational Force < Force applied by the girl to lift the bag.
Answer:
Closed system, because the speed of the car is as expected in the case where an object has uniform acceleration for a time t
Explanation:
Here in the question it is mentioned that a toy car has an initial acceleration of 2m/s² across a horizontal surface so we can say that it is acted upon by an external force
Assuming that the acceleration is constant and the reason for this assumption is there at the last
The major difference between an open system and closed system is in case of open system there will be transfer of matter and in case of closed system there will be no change in matter of the system
If acceleration is constant in case of closed system we can expect the speed of the car after a time t by using the formula
s = u×t + 0·5×a×t²
where s is the distance travelled
t is the time taken to travel that distance
u is the initial velocity
a is the acceleration of that system
But in case of open system as there will be a change of mass there will be a change in velocity of the system so in this case we cannot expect the speed of the car after a time t
And if the acceleration is not constant then we cannot say that the toy car is an open system or closed system, that is why we are assuming that the acceleration of the toy car is constant
Explanation:
Q= mc∆T
∆T= 5-24=- 19
Q= 0.5*4186*-19
Q= -39767 J
negative sign show heat releases
Here in nuclear reaction we can say that sum of neutrons and protons in reactant side and product side will be same always
Here mass number on the product side is given to us
so sum of mass number is given as
now on the reactant side also the number must be same
now we will have
Now number of protons on product side is given as
now we also know that atomic number of Fe is 26
so now we will have
now the equation is given as
