MULTIPLE CHOICE. Choose the one alternative
... 9) An object attached to a spring is pulled across a frictionless surface. If the spring constant is 45 N/m and the spring is stretched by 0.88 m when the object is accelerating at 1.4 m/s2, what is the mass of the object? A) 36 kg ...
... 9) An object attached to a spring is pulled across a frictionless surface. If the spring constant is 45 N/m and the spring is stretched by 0.88 m when the object is accelerating at 1.4 m/s2, what is the mass of the object? A) 36 kg ...
Newton`s 2nd Law Problems
... skateboard at the beginning of the interval and is removed at the end. The skateboard takes 8.5 s to travel the 1.0 m distance, and it then coasts for another 1.25 m before coming to rest. Calculate the force applied to the skateboard, and the constant frictional force apposing its motion. (2.6 x 10 ...
... skateboard at the beginning of the interval and is removed at the end. The skateboard takes 8.5 s to travel the 1.0 m distance, and it then coasts for another 1.25 m before coming to rest. Calculate the force applied to the skateboard, and the constant frictional force apposing its motion. (2.6 x 10 ...
Dynamics of Rotational Motion
... rims. Why does this allow a racer to achieve greater accelerations than would an identical reduction in the mass of the bicycle’s frame? Describe the energy transformations involved when a yo-yo is thrown downward and then climbs back up its string to be caught in the user’s hand. Calculate the mome ...
... rims. Why does this allow a racer to achieve greater accelerations than would an identical reduction in the mass of the bicycle’s frame? Describe the energy transformations involved when a yo-yo is thrown downward and then climbs back up its string to be caught in the user’s hand. Calculate the mome ...
Weightlessness
Weightlessness, or an absence of 'weight', is an absence of stress and strain resulting from externally applied mechanical contact-forces, typically normal forces from floors, seats, beds, scales, and the like. Counterintuitively, a uniform gravitational field does not by itself cause stress or strain, and a body in free fall in such an environment experiences no g-force acceleration and feels weightless. This is also termed ""zero-g"" where the term is more correctly understood as meaning ""zero g-force.""When bodies are acted upon by non-gravitational forces, as in a centrifuge, a rotating space station, or within a space ship with rockets firing, a sensation of weight is produced, as the contact forces from the moving structure act to overcome the body's inertia. In such cases, a sensation of weight, in the sense of a state of stress can occur, even if the gravitational field was zero. In such cases, g-forces are felt, and bodies are not weightless.When the gravitational field is non-uniform, a body in free fall suffers tidal effects and is not stress-free. Near a black hole, such tidal effects can be very strong. In the case of the Earth, the effects are minor, especially on objects of relatively small dimension (such as the human body or a spacecraft) and the overall sensation of weightlessness in these cases is preserved. This condition is known as microgravity and it prevails in orbiting spacecraft.