b. Yes, the force applied is parallel to the direction of motion.
c. No, the force applied is perpendicular to the direction of motion.
d. Yes, the force applied is perpendicular to the direction of motion.
Answer:
No, the force applied is perpendicular to the direction of motion.
Explanation:
Work done is given by :
F = force
d = displacement
= angle between force and displacement
Work is positive when the force and the displacement are in same direction. Work is negative when the force and the displacement are in opposite direction. When the force and displacement are perpendicular to each other, no work is done.
If we carry a book across the room at a constant velocity, the work done is zero. This is because our weight is acting vertically downward and we are moving forward. The angle between the force and the displacement is 90. So, no work is done.
Hence, the correct option is (c) "No, the force applied is perpendicular to the direction of motion".
b) Explain which one(s) hit the ground last
Explanation:
Balls A and C have the same initial vertical velocity of zero. Therefore, they land at the same time.
Ball B has a positive initial vertical velocity, so it hits the ground last.
The mass of water in the kettle is 0.50 kg.
The specific heat capacity of water is 4200 J/kg °C.
The initial temperature of the water is 100 °C.
Calculate the average power output from the water in the kettle to the surroundings in 2 hours
Answer:
4 A
Explanation:
V = IR, where V=voltage, I=current, R=resistance. This is Ohm's Law. (remember that for units V = volts, Ω = ohms, A = amperes.)
V = IR
12 V = I * 3 Ω
12/3 = I
I = 4 A