If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
<u>fr = -40 N</u>
Answer:
Rechargeable batteries can still go flat after repeated use because the materials involved in the reaction lose their ability to charge and regenerate
Explanation:
they go flat because they a rechargeable and sometimes don't always work
thank you hope u have a good day
O.99 m long .simple pendulum time period is 2s for second formula then use formula T=2pi.rt(lenght/gravity)
