6. Intro to Forces (Dynamics)

When a pair of $10-N$ forces act on a box of candy in opposite directions, what is the net force on the box?

A block of mass $m$ is attached to a light, inextensible cable and hangs vertically. The system is released from rest with the cable taut. According to Newton's Second Law, what is the magnitude of the acceleration of the block immediately after release, neglecting air resistance?

A $4.50$-kg experimental cart undergoes an acceleration in a straight line (the $x$-axis). The graph in Fig. E$4.13$ shows this acceleration as a function of time. Find the maximum net force on this cart. When does this maximum force occur?

An astronaut is inside a $2.25\times {10}^6$ kg rocket that is blasting off vertically from the launch pad. You want this rocket to reach the speed of sound ($331$ m/s) as quickly as possible, but astronauts are in danger of blacking out at an acceleration greater than $4g$. What is the maximum initial thrust this rocket's engines can have but just barely avoid blackout? Start with a free-body diagram of the rocket.

The 100 kg block in FIGURE EX7.24 takes 6.0 s to reach the floor after being released from rest. What is the mass of the block on the left? The pulley is massless and frictionless.

Under which flight condition does the $p$-factor cause an airplane to yaw to the left?

According to Newton's Second Law, which equation correctly expresses how to find the applied force acting on an object of mass $m$ experiencing an acceleration $a$?

Which of the following statements about dynamics is correct?

A heavy steel cable attached to a motor is lifting a girder, and the girder is speeding up. Which of the following statements best describes the forces acting on the girder according to Newton's Second Law?

According to Newton's First Law, can there be forces acting on an object that is at rest?

A block of mass $m_1$ is initially at rest on a frictionless horizontal surface. A constant force $F$ is applied to the block for a time interval $t$. What is the final speed $u_f$ of block 1 at the end of the time interval?

According to Newton's Second Law, if the net force acting on an object is doubled while its mass remains constant, what happens to the object's acceleration? $F=ma$

If your physics textbook is sliding to the right across a horizontal table and slowing down, which of the following statements best explains the $\mathrm{net} \mathrm{force}$ acting on the book?

Which statement is true according to Newton's First Law of Motion?