Search & Filtering
A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds.What is his acceleration?Is this acceleration higher than that of a car which accelerates from 0 to 30 m/s in 8 seconds ?
A person has a reasonable chance of surviving an automobile crash if the deceleration is no more than 30 g's.
a. Calculate the force on a 68-kg person accelerating at this rate.
b. What distance is traveled in meters if brought to rest at this rate from 95 km/h?
Suppose the mass of a fully-loaded module in which astronauts take off from the Moon is 20,000 kg. The thrust of its engines is 70,000 N. The acceleration due to gravity on the moon is 1.51 m/s2.
Calculate the magnitude of acceleration in a vertical takeoff from the Moon.
Cobalt-60, with a half-life of 5.3 years, has a number of
applications, including medical therapy and the sterilization
of medical tools. Determine the mass of a 50 g sample that
would remain after
(a) 6 months
(b) 5 years
4. In the circuit shown on the right, the rate at which R1
dissipating electrical energy is 20.0W.
(a) Find R1 and R2.
(b) What is the emf of the battery?
(c) Find the current through both R2 and the 10.0-Ω
resistor.
(d) Calculate the total electrical power consumption in all
the resistors and the electrical power delivered by the battery
3. A triangular array of resistors is shown in the figure on the
right. What current will this array draw from a 35.0V battery
having negligible internal resistance if we connect it across
a.) ab;
b.) bc and
c.) ac?
The circuit in the figure on the right shows a network of resistors
connected in series and in parallel.
(a) Determine the total resistance of the network.
(b) What is the current through the 3.00-Ω?
A body vibrate in simple harmonic motion with a frequency of 50hz and an amplitude of 4cm. Find
1.period
2. Acceleration at the middle and at the end of the path of oscillation
An elevator of mass 1500 kg is at rest and then begins to ascend at an acceleration of 1.0 m / s² . A constant frictional force of 800 N retards its motion upward . ( a ) Find the tension in the cable carrying the elevator . ( b ) Find the minimum power delivered by the motor at t = 4s while the elevator is moving upward . ( c ) What will be the reading on a bathroom scale if a 50 kg person stands on it while the elevator is ascending ?
The forces acting on a body(s) are :F1=30n(60 north of west) f2=40 N (30 north of west)
a-represent the forces acting on (s) on a free body diagram
b-Calculate the magnitude of the net force acting on (s) and indicate its direction
