What do You mean by The Effiency is 80% of Simple Manchine?

A1,700kg car is being used to give a 1,400kg car a push start by exerting a force of 140n the impulse on the smaller car during the 30.0s of contact is +670kg*m/s. what is the impulse of the smaller car on the larger car? -814 kg*m/s 0kg *m/s -670kg*m/s -550kg*m/s

=force × distance a. work b. velocity c. pressure d. momentum

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?