Recent content by JeremyG

N3L does apply for Fa, but it is an external force and its origin is from some external body, so we only see the effect on M2. As far as M1 is concerned, Fa is non-existent. So where does the pushing force on M1 come from you might ask? Well, from your FBD of M1, it becomes apparent that this...

Yes you can still use Newton's Law. It would be most useful to consider the torque about the rotation axis, which would passing through the hinge in your question. So net torque, ##\sum\tau = F\times r = I\alpha## . In the above equation, everything should be taken with respect to the rotation...

It is possible to use the rotational analogue of Newton's law, just be careful of the Moment of Inertia that you use in your equations. The Moment of Inertia must be taken about the rotation axes. Also, if I'm not wrong, ##\tau = I\alpha ## holds only if the axis is fixed. The only exception is...

No attempt?

They will be, in time. As long as heat can flow from brick I to brick II (or vice versa) using brick III as a medium, they are considered to be in thermal contact. It does not mean physical contact, as u/Bystander pointed out.

No problem! Glad to help! :)

1. For projectile motion, neglecting air resistance, the horizontal component of the velocity remains constant. The only force acting on the projectile during this parabolic motion is its own weight, in the vertical direction. 2. At its highest point, what is its vertical and horizontal speed...

If this is all you need to find then there's no need for considerations of energy, work or whatever goes on at the curved track. It is simply a projectile motion question. What is the speed of a projectile at its highest point? Think in terms of the vertical and horizontal speeds

The object will not stop immediately when the force drops to 4N. Remember that the net force only causes a deceleration and Force does not equal to motion. But back to your question about friction: say the pushing force experienced by the object is 4N (at t2). The net force is now -1N. By...

Yes, you have the general idea. The key in both of the situations I stated was in the time of contact between the two objects. This is a concept known as impulse, or better known as change in momentum. If the time of contact is short, as in the tennis racquet with taut strings, then the impulse...

Momentum is an important concept not just theoretically but we use it in our lives everyday. Momentum is the reason why we have airbags in our cars instead of metal steel plates. In a car crash, both airbags and metal steel plates will serve well in applying a stopping force on the driver, but...

Torque by the thrower is the cause for the tangential acceleration/angular acceleration of the discus. And as mentioned above, the thrower himself need not be considered in this problem. The discus is traveling in a circular motion, yes? Tangential acceleration is not sufficient to ensure that...

Yes, the question wants the total acceleration, so that should give you a clue that it is not just tangential acceleration at play here. What else?

Yes in this case you can treat it as a particle going round in a circle. ##a = r\alpha## will give you what kind of acceleration? As a hint, see the comment below as well. You mean 9rad/s? No you do not ignore this.

Not necessary. The question is interested in the acceleration of the discus, so there is only a need to consider the motion of the discus.