That's not true people that have a broken leg use crutches and the constant lifting of their own body weight will help them gain muscle
7.5 I think because it can not be 9 because it’s not close to 50
Answer:
Work done on an object is equal to
FDcos(angle).
So, naturally, if you lift a book from the floor on top of the table you do work on it since you are applying a force through a distance.
However, I often see the example of carrying a book through a horizontal distance is not work. The reasoning given is this: The force you apply is in the vertical distance, countering gravity and thus not in the direction of motion.
But surely you must be applying a force (and thus work) in the horizontal direction as the book would stop due to air friction if not for your fingers?
Is applying a force through a distance only work if causes an acceleration? That wouldn't make sense in my mind. If you are dragging a sled through snow, you are still doing work on it, since the force is in the direction of motion. This goes even if velocity is constant due to friction.
Explanation:
C. Series
Consider resistors in a circuit - if all the resistors in the circuit are in series and one of the resistors fails then no current can flow thru the circuit,
If the resistors are in parallel then then each resistor experiences the same voltage drop regardless of whether or not any resistor in particular is carrying current.
Answer:
54 km/h
Explanation:
given,
speed of the biker = 36 Km/h
time = 10 s
acceleration = 0.5 m/s²
speed at which it crosses the finish line = ?
v = 36 x 0.278 = 10 m/s
using equation of motion
v = u + a t
v = 10 + 0.5 x 10
v = 15 m/s
v = 15 x 3.6 = 54 km/hr
speed at which the biker crosses the finish line is equal to 54 km/h
