It is so because the steel is more colder than our body.
The components of the resultant will be: (18, 12)
In order to find the magnitude you have to apply the Pythagorean theorem:
√(18² + 12²) = √468 = 21.6
Therefore, the magnitude of the resultant vector is 21.6
The direction is given by the formula:
α = tan⁻¹(v_y / v_x)
= <span>tan⁻¹(12/18)
= 33.7°
Therefore, the direction will be 33.7° from the x-axis.</span>
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
Answer:
45000 kg and 45 tons
Explanation:
The expression in kilograms and tons is shown below;
As we know that
1 gr is 0.001 kg
So, 45000000 = 45,000 kg
And,
1 kg = 0.001 tons
So, 45000 kg = 45 tons
Therefore the same would be considered
Answer: 321 J
Explanation:
Given
Mass of the box 
Force applied is 
Displacement of the box is 
Velocity acquired by the box is 
acceleration associated with it is 
Work done by force is 
change in kinetic energy is 
According to work-energy theorem, work done by all the forces is equal to the change in the kinetic energy
![\Rightarrow W+W_f=\Delta K\quad [W_f=\text{Work done by friction}]\\\\\Rightarrow 375+W_f=54\\\Rightarrow W_f=-321\ J](https://tex.z-dn.net/?f=%5CRightarrow%20W%2BW_f%3D%5CDelta%20K%5Cquad%20%5BW_f%3D%5Ctext%7BWork%20done%20by%20friction%7D%5D%5C%5C%5C%5C%5CRightarrow%20375%2BW_f%3D54%5C%5C%5CRightarrow%20W_f%3D-321%5C%20J)
Therefore, the magnitude of work done by friction is 
