Friction pulls directly against the direction of motion (at 180) of a sled, and does -55.2 J of work while the sled moves 8.98 m
1 answer:
The magnitude of the force of friction is 6.1 N
Explanation:
The work done by a force when moving an object is given by the equation:
where :
F is the magnitude of the force
d is the displacement
is the angle between the direction of the force and of the displacement
In this problem, we have:
W = -55.2 J (work done by the force of friction)
d = 8.98 m (displacement of the sled)
(because the force of friction acts opposite to the direction of motion)
By solving the equation for F, we find the magnitude of the force of friction on the sled:
Learn more about work:
#LearnwithBrainly
You might be interested in
At stp conditions (
), the speed of sound is
The sound wave moves by uniform motion, so we can use the basic relationship between space, time and velocity:
where S is the distance covered by the sound wave in a time t. In our problem, t=3.00 s, therefore the distance covered by the sound wave is
The sound wave moves by uniform motion, so we can use the basic relationship between space, time and velocity:
where S is the distance covered by the sound wave in a time t. In our problem, t=3.00 s, therefore the distance covered by the sound wave is
The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.
The current flowing through the lamp is given by Ohm's law:
where
V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.
The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.