Answer:
s₁ = 0.022 m
Explanation:
From the law of conservation of momentum:
where,
m₁ = mass of hockey player = 97 kg
m₂ = mass of puck = 0.15 kg
u₁ = u₂ = initial velocities of puck and player = 0 m/s
v₁ = velocity of player after collision = ?
v₂ = velocity of puck after hitting = 48 m/s
Therefore,
negative sign here shows the opposite direction.
Now, we calculate the time taken by puck to move 14.5 m:
Now, the distance covered by the player in this time will be:
<u>s₁ = 0.022 m</u>
Answer : (A) A charged object is brought near a neutral object without touching it.
Explanation:
Bodies can be charged by the method of conduction. By conduction the body acquires the same charge as on the charging body.
Charging the body can be understood by the following example of charging a paper cylinder by conduction. Make a paper cylinder by rolling a strip of paper on a pencil and then gently pulling out the pencil. Suspend the paper cylinder by a string tied to its center, now touch the paper cylinder with a glass rod rubbed with silk so it has a positive charge. Remove the class rod and the again bring it near to the paper cylinder.
The paper cylinder is repelled by the positively charged rod. And when you bring a negatively rubbed rod, next to the cylinder it will be attracted towards the rod. This means that the paper cylinder has acquired a positive charge as on the glass rod due to conduction.
The normal force is the supporting force that is exerted on an object that is in contact with another stable object.
Answer: Option C
<u>Explanation:
</u>
Normal force is forward or upward pushing force acting on an object. Mostly the normal force acts as supporting force exerted on the object by the neighbouring stable object with which the object in question is in contact. So normal force falls under the category of contact forces.
Generally, normal force will be acting to support the weight of any object placed on another object. The best examples of normal forces are the weight of the book supported by table or by the pushing force of the wall on the person leaning on the wall.
It’s a vector quantity, which means it possesses both magnitude and direction. So the SI unit would be B)kg•m/s
By definition of average acceleration,
<em>a</em> = (20 m/s - 33.1 m/s) / (4.7 s) ≈ -2.78 m/s²
Vertically, the car is in equilibrium, so the net force is equal to the friction force in the direction opposite the car's motion:
∑ <em>F</em> = (1502.7 kg) (-2.78 m/s²) ≈ -4188.38 N ≈ -4200 N
If you just want the magnitude, drop the negative sign.